Optical apparatus for measuring tooling position within a seaming machine

ABSTRACT

The present invention provides an optical device for measuring characteristics of toolings ( 116 ), especially chuck and roll in a seamer. The optical device comprises a radiation source ( 102 ) adapted to generate radiation, means ( 106, 108 ) for diverting the radiation so as to pass through a profile in the toolings ( 116 ), and a detector ( 114 ) adapted to receive the radiation that passed through the profile. The characteristics of the toolings ( 116 ) such as the profiles of a gap between the chuck and the roll, are processed from the detected radiation that passes through the profile.

FIELD OF THE INVENTION

The present invention relates to optical devices. More particularly, thepresent invention relates to an optical apparatus for measuringparameters related to toolings, relative distance and quality.

BACKGROUND OF THE INVENTION

Seamers are used in the industry for closing beverage, food, and aerosolcans, as well as other enclosures such as oil drums, oil filters andeven capacitor enclosures, before and after these containers are filled.Seaming the cans has been known in the industry for decades and ensuresthat the closure between the can's cover and the can's body is sealedand safe enough so that the content does not leak and outside hazardscannot enter the enclosure through the seams. There is no contact ofheat, dirt, or hazardous materials with the contents of the enclosure byusing seaming methods.

In present-day seamers, there are two phases during the seaming process.A chuck is a tooling that operates within the seamer and holds the can(a container or enclosure) in position while the seamer is turning. Afirst operation roll then approaches the can and pushes the body andcover into one another while rotation performs the operation around thecircumference of the can. At this point, the first operation roll movesaway and a second operation roll, with a different profile shape exertspressure on the cover and body so that the final seam is tight enoughand that it is sealed properly.

Seamers often have more than one head so that several cans can be closedsimultaneously. Each one of the head's chuck and rolls are atintermediate positions during the seaming process.

With today's high speed manufacturing requirements, seamers as well asother procedures that take part in the filling and manufacturing of cansare expected to increase in speed. As speeds increase, there are morepotential problems with the seams due to the inaccurate positioning ofthe tooling with reference to one another (one tooling against theother) during the seaming procedure.

Once a problem in a seamer is detected, the seamer must be completelystopped (all heads are affected) and the appropriate manufacturinghead's tooling must be adjusted. The cans that were incorrectly seamedmust be located and thrown away (most likely, it is too late and thecans manufactured by a particular head and many more than necessary arethrown away). The incorrectly positioned tooling must be quicklyadjusted in order to continue the manufacturing process.

In addition, tight clearances, which are the distances between the chuckand rolls, may cause friction between the roll and the chuck and couldcause one or the other to shatter—which might damage the seamer andpossibly introduce dangerous material into the cans. Tight clearancesmight also exert unnecessary pressure on the seams, which could causethe seam to weaken, or even ultimately break, or be misshapen in a waythat could damage the users (e.g., by scratching them).

Clearances that are not tight enough could cause an open seam, whichmight introduce hazards into the enclosure, or allow the contents of theenclosure to escape or be contaminated.

Small initial variations in the distances between the rolls and thechuck throughout the seamer heads will increase due to the pressuresexerted on the tooling during the manufacturing process. Over time, thevariations between the heads will increase substantially. This willresult in subsequently having to stop the seamer several times, once foreach head that has gone out of alignment, instead of once for all theheads.

Measurements of the distances between the toolings are done in the apexof the motion of the roll against the chuck. This is the point where thetoolings are at the closest possible position to each other during themanufacturing process. The seamer manufacturer marks the specificposition on the seamer (there is a range where the distance will notchange, wherein this distance approximately equals the circumference ofthe can being seamed).

The state of the art methods of measuring tooling characteristics are asfollows:

-   1. Measuring the thickness, which is the smallest distance through    the range of motion between the roll and the chuck, by inserting    feeler gauges (also known as filler gauges) between the roll and the    chuck tooling. If a feeler gauge (larger than the specific distance)    cannot be inserted between the tooling and a second feeler gauge    (smaller than the specific distance) can be inserted between the    tooling—the distance is assumed to be correct. This method is    subjective as it is too difficult to accurately verify that the    distance is within the specification after the use of feeler gauges.-   2. Measuring the clearance, which is the vertical position of the    chuck and the roll. The clearance is usually measured by measuring a    point on the roll against a reference point. Then, the chuck's known    position is measured against the same reference point (usually the    can holder platform). The difference between the two measurements is    a representation of the vertical distance between the roll and    chuck. This method is complex and almost impossible to perform    accurately as small inaccuracies on the roll itself or in the gauge    can cause a major inaccuracy in the measurements. Both the clearance    and thickness measurements are interactive—modifying one can easily    alter the other, so measuring them and adjusting them individually,    as it is done today, is incorrect and inaccurate.

This procedure must be carried out separately for the first and secondoperation rolls and the chuck for each head. The procedure is relativelylong; thus stopping the manufacturing process for a relatively longperiod of time. At the same time, the procedure is prone to inaccuraciesand disadvantages such as: mistakes in the first operation roll positionare not apparent and can cause issues that are difficult if notimpossible to detect and correct; Because of production requirements, itis often impossible to remove second operation rolls once they areinstalled (in order to reposition the first operation rolls);Experienced operators are needed; The procedure does not allowdetermination of the optimal positions of the rolls and chucks in orderto produce correct seams; The procedure is expensive since many cans arethrown away; Finally, the procedure is extremely time consuming.

It is a long felt need to provide a method for measuring the distancebetween the tooling and the clearance that is efficient and quick.According to the present invention, use of an optical device is highlyefficient and accurate as well as relatively quick and economical due toeliminating both the need to remove rolls and the need to throw awayexcessive amount of cans.

The use of optical devices for evaluating and inspecting surfaces,profiles, and dimensions is known in the industry. Devices that arerelevant to the present invention are profilers. Profilers based onlight projection are also known. An example is disclosed in patent U.S.Pat. No. 4,983,043 “High accuracy structured light profiler”, filed byHarding in 1988. This optical gauging system for evaluating the surfaceshape includes an illumination system which projects a line of lightonto a work piece surface, a viewing system focused along that line. Thefocused line is imaged onto a linear detector array. A translationmechanism is also provided so that the relation between the translationmechanism and the output of the array is related to the profile shape. Amethod for measuring contours is disclosed in U.S. Pat. No. 5,612,786“Contour measurement system” filed by Huber in 1995. The optical systemis activated to obtain a set of data that is being optimized andcalibrated so as to obtain the contours of a three dimensional object.

Another example of a profiler is in U.S. Pat. No. 5,986,745 “Co-planarelectromagnetic profile scanner”, filed by Hermary in 1997. Thisco-planar system for determining the shape and dimensions of a surfaceof an object includes a projector, a receiving device and adiscriminator for determining which portion of the reflected patterncorresponds to which portion of the projected pattern. The resultingsignals and correlations are used to calculate the shape and dimensionsof the object.

None of the above mentioned optical devices as well as other devices canbe applied for determining the distance and clearance between the firstand second operation rolls and the chucks of the present invention.There was a need to establish an optical device by which the distancebetween the tooling in the seamer can be accurately determined, whilethe chuck and the rolls are installed in the seamer.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an optical devicefor measuring tooling characteristics especially designed for measuringthe profile characteristics of the gap between a chuck and a roll in aseamer.

It is another object of the present invention to provide an opticaldevice for measuring tooling characteristics in a relatively narrow areawhile maintaining little or no distortion of the light adapted to carrythe resulted information.

Therefore, and in accordance with a preferred embodiment of the presentinvention, there is provided an optical device for measuringcharacteristics of toolings, said optical device comprising:

-   -   a radiation source adapted to generate radiation;    -   means for diverting said radiation so as to pass through a        profile in the toolings;    -   detector adapted to receive said radiation that passed through        the profile;

whereby the characteristics of the toolings are processed from thedetected radiation that passes through the profile.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the toolings are chuck and roll in a seamer and thecharacteristics are the profiles of a gap between the chuck and theroll.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said radiation is selected from a group consisting ofelectromagnetic radiation, light radiation or laser light.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said optical device further comprises at least onebeam expander so as to generate a coherent beam.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said at least one beam expander is comprised of twolenses that expand the beam with a minimal dissipation.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said means for diverting said radiation is selectedfrom a group of diverters such as mirror, lens, or fiber-optic.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said means for diverting the radiation is a prism.

Furthermore, in accordance with another preferred embodiment of thepresent invention, a first prism diverts the radiation towards theprofile and wherein said second prism diverts the radiation that passesthrough the profile.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said detector and said source are positioned side byside and said first prism and said second prism are positioned in apredetermined distance and opposite to one another so as to form abypass of said radiation.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said optical device further comprises a magnificationsystem adapted to receive radiation that passes through the profile andtransfers it so as to hit said detector.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said detector is a CCD camera, CMOS camera, oranother type of digital or analog radiation detector.

Furthermore, in accordance with another preferred embodiment of thepresent invention, characteristic of toolings is a distance between thetoolings.

Furthermore, in accordance with another preferred embodiment of thepresent invention, characteristic of toolings is a clearance between thetoolings, shape of toolings, or distances in the gap between toolings.

It is thus provided in accordance with yet another preferred embodimentof the present invention a method for measuring characteristics oftoolings comprising:

-   -   providing a radiation source adapted to generate radiation;    -   providing a first means for diverting said radiation so as to        pass through a profile of the gap between the toolings;    -   providing a second means for diverting said radiation that        passes through the profile;    -   directing the diverted radiation to a detector;

whereby the characteristics of the toolings is processed from thedetected radiation that passes through the profile.

Furthermore, in accordance with another preferred embodiment of thepresent invention, said radiation is selected from a group consisting ofelectromagnetic radiation, light radiation or laser light.

Furthermore, in accordance with another preferred embodiment of thepresent invention, the toolings are chuck and roll in a seamer and thecharacteristics are the profiles of a gap between the chuck and theroll.

additionally, in accordance with another preferred embodiment of thepresent invention, said first means for diverting and said second meansfor diverting said radiation are selected from a group comprisingdiverters such as prism, mirror, lens, or fiber-optic.

BRIEF DESCRIPTION OF THE FIGURES

In order to better understand the present invention and appreciate itspractical applications, the following Figures are attached andreferences herein. Like components are denoted by like referencenumerals.

It should be noted that the figures are given as examples and preferredembodiments only and in no way limit the scope of the present inventionas defined in the appending Description and claims.

FIG. 1 illustrates a schematic top representation of a roll and a chuckfor which profiles and distances have to be measured by the representedprojected light in accordance with the physical principle of the presentinvention.

FIG. 2 illustrates a schematic frontal view of an optical device formeasuring tooling characteristics in accordance with a preferredembodiment of the present invention, positioned between a chuck and aroll from which characteristics are taken.

FIGS. 3 a-c illustrate an isometric, side and frontal view of theoptical device for measuring tooling characteristics shown in FIG. 2.

FIG. 4 illustrates a shadow-graph resulting from the present invention'smeasurement of tooling using an optical device for measuring toolingcharacteristics.

DETAILED DESCRIPTION OF THE INVENTION AND FIGURES

The present invention provides a new and unique means for measuringprofiles of tooling so as to establish characteristics such as distanceand clearance, especially for quantifying the performance of tooling inseamers. The methods used nowadays for measuring the distance and theclearance in seamers so as to provide quality estimates are prone toinaccuracies as well as time consuming and costly. It has been a longfelt need in the industry to provide an accurate method that willestablish quick and accurate quality results for the seams produced bythe seamers.

Reference is made to FIG. 1 illustrating a schematic top representationof a roll and a chuck for which profiles and distances have to bemeasured by the represented projected light in accordance with thephysical principle of the present invention. The basis of the method ofthe present invention is establishing a shadow-graph by which atwo-dimensional profile of the area between a specific roll and chuck,the gap between them, is produced. In FIG. 1, the top view illustrates aroll 10 and a chuck 12. Light is transmitted between roll 10 and chuck12 from point 14 to point 16. Roll 10 and chuck 12 partially blocks thelight so as to allow only light that passes through the gap between themto reach point 16 and to establish a shadow-graph.

It is optional to use any kind of electromagnetic radiation such aslight or laser to be transmitted from point 14 while the electromagneticwaves that pass between roll 10 and chuck 12 are collected in point 16using any type of detector according to the type of radiation used. Thedetector that receives and detects the radiation will produce a profileof the gap between roll 10 and chuck 12 in two axes: a vertical axisthrough which the clearance is measured, and a horizontal axis throughwhich the thickness is measured. At the point where the seamer ispositioned, the thickness is the minimal thickness distance between theroll and the chuck.

Due to requirements to perform the quality examination while theseamer's heads have already been installed, there was a need to producean optical apparatus in which the light passes through the gap betweenthe tooling without having the whole apparatus in the gap since there isno room for the whole apparatus. Therefore, the optical apparatus of thepresent invention has means to divert the electromagnetic radiation intothe gap with little or no distortion.

Reference is now made to FIG. 2 illustrating a frontal view of anoptical device for measuring tooling characteristics in accordance witha preferred embodiment of the present invention, positioned between achuck and a roll from which characteristics are taken. Chuck 50 and roll52 are installed in a seamer (the machinery itself is not shown in thefigures) side by side while the rolls (a first operation roll and then asecond operation roll) approach the can (the can is not shown in FIG. 1)and pushes it into one another while rotating about the circumference ofthe can to ensure that the closure is indeed secure. As mentioned hereinbefore, qualitatively characterizing the profile between the roll andthe chuck is enormously significant in order to assure the closure ofthe can. Optical device 100 is positioned between chuck 50 and roll 52while prisms 108 and 110 are positioned on both sides of the chuck andthe gap between the roll in the height of the point being measured (onlyone prism is shown in FIG. 2, the other one is concealed by the frontalone). This Figure illustrates the positioning of the optical device ofthe present invention relative to the chuck and the roll.

In order to better understand the mechanism of the optical device of thepresent invention, reference is now made to FIGS. 3 a, b, and cillustrating isometric, side and frontal views of the optical device formeasuring tooling characteristics shown in FIG. 2. A light transmitter,possibly having a laser light source 102, transmits light upwardly. Adoted line 104 indicates the direction of the beam. The transmittedlight can be any electromagnetic radiation.

The light projected of laser light source 102 is collimated as itemerges from opening 105 (shown clearly in FIG. 3 a) and then passesthrough beam expander. The beam expander is comprised of two lenses 106that expand the beam with a minimal dissipation. Lens 106 produces anddirects a coherent light beam that hits a first prism 108. First prism108 diverges the direction of the beam from 104 to 104′ in substantially90 degrees, so that the beam hits a second prism 110, positionedopposite first prism 108. The objects to be measured 116, in this case,the roll and the chuck (not shown in FIG. 3) is placed in the pathway ofthe projected radiation substantially in the center of direction of line104′, where the measurement is taken. The positioning of the object tobe measured is shown in FIG. 3 a.

It should be noted that other techniques for beam expansion can be usedand are covered by the scope of the present invention. Beam expansionmay not be necessary when a suitable electromagnetic radiation source isused that has a sufficiently large diameter of radiation that canencompass the area being probed.

Returning to FIG. 2, first prism 108 and second prism 110 (obscured bythe first prism) are positioned horizontally in the level of themeasuring point between roll 52 and chuck 50. The measured point wherethe profiles to be characterized are provided is placed in the axisbetween the prisms—in direction 104′ of the laser light. The beamprojected from first prism 108 to second prism 110 passes through thegap between chuck 50 and roll 52. Such arrangement of the prismsprevents the system from producing a distorted view of the area betweenthe roll and the chuck. Another significant advantage of the arrangedapparatus is that the measurement is performed whilst the roll and thechuck are installed within the seamer and there is no need to removethem. Since the measurement is performed within the seamer, theadjustment can be performed as the system provides a measurement result.This allows a quick and easy deterministic adjustment of the rollagainst the chuck.

Reference is made again to FIG. 3. Second prism 110 diverts thedirection of the laser light 104′ downwards in the direction indicatedby dotted line 104″. The resulting light that passes through this linealready carries information regarding characteristics of the gap betweenthe chuck and the roll since the only light that can pass through thisgap will be received by second prism 110 and be diverted downwards.Light that does not pass through the gap will reflect outwards and willnot interfere with the measurements.

First prism 108 and second prism 110 basically act as a transmissionmedium for the light and since there is no room for the light source orthe detector in the area to be detected only the gap between the chuckand the roll will be measured. Other means to divert and transmit thelight from one side of the area to be detected to the other side can beused. Optionally, mirrors can be used so as to establish the routing ofthe light from the source to the detector. Another alternative is to usea fiber-optic technique or lenses in order to divert and transmit thelight freely through the gap between the chuck and the roll. Everyavailable technique to divert the light or the electromagnetic radiationto the measured area and from it may be used in order to build theapparatus of the present invention. Every such diverting means iscovered by the scope of the present invention. Optionally, the light canbe produced within the opening itself, this option as well as others isalso covered by the scope of the present invention.

The light projected from second prism 110 passes through magnificationsystem 112 that comprises magnification lenses. The system can be aregular system that is used in optical devices so as to facilitate theinterpretation of the results. Eventually, the resulting light hits anelectromagnetic detector, preferably CCD camera 114. Other detectingmeans for electromagnetic radiation can be used in order to digitize theresults such as camera or CMOS camera that are covered by the scope ofthe present invention. CCD camera 114 collects the results from thelight that carries information regarding characteristics of the gapbetween the chuck and the roll, preferably in the shape of a shadowgraph; thus revealing the characteristics of the vertical dimension—theclearance and the horizontal dimension—the thickness. The digitized datais interpreted through suitable software (not shown in the figures) andis displayed as the clearance and thickness, either automatically orthrough the aid of an operator.

It should be noted that different measurement values (e.g., clearanceand thickness) may be separately measured at different positions alongthe motion of the seamer, where it may be most appropriate (where theimage might be clearer) or comfortable for the operator to perform thesemeasurements without significantly skewing the measurement results ofthese values.

Reference is now made to FIG. 4 illustrating a shadow-graph resultingfrom a measurement of tooling using an optical device for measuringtooling characteristics in accordance with a preferred embodiment of thepresent invention. The shadow indicated by 200 is the shadow of a chuck.The shadow indicated by 201 is the shadow of a roll. Both roll and chuckare in a seaming machine. The brighter area is the gap between chuck 200and roll 201. The characteristics that are measured between the chuckand the roll are the thickness (the distance) that is indicated bydouble headed arrow 203, the clearance that is indicated by two arrows202 and a chin indicated by double headed arrow 204. As can be seen, themeasured characteristics, which are indicated in a table on the right,have very small dimensions; however, the results are very accurate.

It is emphasized that other features characterizing the profile betweenthe chuck and the roll can be measured such as the shape of the profileof the chuck or of the roll, as well as radius, angles or distances ofshapes formed between the chuck and the roll. Any characteristic thatprovides quantitative information regarding the gap between the roll andthe chuck is covered by the scope of the present invention.

It should be noted that the measurements of clearance and thickness arevery quick and accurate using the present invention. This is due to thefact that the measurement is performed directly on the chuck and rollwhen they are in their actual positions. The measurements can beperformed on the first operation roll as well as on the second operationroll. According to the methods that are presently the state of the art,the measurements are performed indirectly, on the final product, usinginaccurate and time-consuming methods. Present methodology interpretsfirst-operation positions from the resulting seam, as these results arenot being directly measured.

The apparatus for measuring quality of tooling of the present inventionprovides accurate results regarding the characteristics of the chuck andthe rolls and significantly facilitate the reduction of initialvariations between the seamer's heads. The reduction in the variationsbetween the heads will produce much more homogenous stopping rates fromthe different heads. While using the methods used presently, when aspecific head goes out of specification, it's most likely that theentire seamer (all of the heads) will require readjustment and not justthe specific defective head. By reducing the number of production stopsfor head readjustment, the final product is much more reliable and bearsfewer faults. This will result in more economical procedures.

The accurate method of the present invention will facilitate predictingwhen the seamer has to go through a quality check stop. This predictionwill allow the companies to forecast these manufacturing stops andperform them at their convenience.

It should be clear that the description of the embodiments and attachedFigures set forth in this specification serves only for a betterunderstanding of the invention, without limiting its scope as covered bythe following claims.

It should also be clear that a person skilled in the industry, afterreading the present specification can make adjustments or amendments tothe attached Figures and aforementioned embodiments that would still becovered by the following claims.

1. A device for measuring characteristics of a gap between a chuck and aroll in a seamer, said device comprising: a radiation source capable ofgenerating radiation; a diverter for diverting said radiation so as topass through a profile in the gap between a chuck and a roll in aseamer; and a two-dimensional array detector capable of receiving saidradiation that passed through the profile, whereby the characteristicsof the profile of the gap are processed from the detected radiation thatpasses through the profile.
 2. The device as claimed in claim 1, whereinsaid radiation is selected from the group consisting of electromagneticradiation, light radiation, and laser light.
 3. The device as claimed inclaim 1, further comprising at least one beam expander so as to generatea coherent beam.
 4. The device as claimed in claim 3, wherein said atleast one beam expander is comprised of two lenses that expand the beamwith a minimal dissipation.
 5. The device as claimed in claim 1, whereinsaid diverter is selected from the group consisting of a prism, mirror,lens, and fiber-optic.
 6. The device as claimed in claim 1, wherein saiddiverter is a prism.
 7. The device as claimed in claim 6, wherein afirst prism diverts the radiation towards the profile and wherein asecond prism diverts the radiation that passes through the profile. 8.The device as claimed in claim 7, wherein said two-dimensional arraydetector and said source are positioned side by side and said firstprism and said second prism are positioned in a predetermined distanceand opposite to one another so as to form a bypass of said radiation. 9.The device as claimed in claim 1, wherein said two-dimensional arraydetector is a CCD camera.
 10. The device as claimed in claim 1, whereinthe characteristics of the gap are a distance between the chuck and theroll.
 11. The device as claimed in claim 1, wherein the characteristicsof the gap are the clearance between the chuck and the roll.
 12. Amethod for measuring characteristics of a gap between a chuck and a rollin a seamer comprising: providing a radiation source capable ofgenerating radiation; providing a first diverter for diverting saidradiation so as to pass through a profile in the gap; providing a seconddiverter for diverting said radiation that passes through the profile;and directing the diverted radiation to a two-dimensional arraydetector, whereby the characteristics of the profile are processed fromthe detected radiation that passes through the profile.
 13. The methodas claimed in claim 12, wherein said radiation is selected from thegroup consisting of electromagnetic radiation, light radiation, andlaser light.
 14. The method as claimed in claim 12, wherein said firstdiverter and said second diverter are selected from the group consistingof a prism, mirror, lens, and fiber-optic.